Messages in this thread | | | Subject | Re: [PATCH] virtio/ringtest: fix up need_event math | From | Jason Wang <> | Date | Thu, 26 Oct 2017 20:28:21 +0800 |
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On 2017年10月26日 09:48, Michael S. Tsirkin wrote: > last kicked event index must be updated unconditionally: > even if we don't need to kick, we do not want to re-check > the same entry for events. > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > tools/virtio/ringtest/ring.c | 24 +++++++++++++++--------- > 1 file changed, 15 insertions(+), 9 deletions(-) > > diff --git a/tools/virtio/ringtest/ring.c b/tools/virtio/ringtest/ring.c > index 6b70c4e..d044a88 100644 > --- a/tools/virtio/ringtest/ring.c > +++ b/tools/virtio/ringtest/ring.c > @@ -196,16 +196,18 @@ bool enable_call() > > void kick_available(void) > { > + bool need; > + > /* Flush in previous flags write */ > /* Barrier C (for pairing) */ > smp_mb(); > - if (!need_event(event->kick_index, > - guest.avail_idx, > - guest.kicked_avail_idx)) > - return; > + need = need_event(event->kick_index, > + guest.avail_idx, > + guest.kicked_avail_idx); > > guest.kicked_avail_idx = guest.avail_idx; > - kick(); > + if (need) > + kick(); > } > > /* host side */ > @@ -265,14 +267,18 @@ bool use_buf(unsigned *lenp, void **bufp) > > void call_used(void) > { > + bool need; > + > /* Flush in previous flags write */ > /* Barrier D (for pairing) */ > smp_mb(); > - if (!need_event(event->call_index, > + > + need = !need_event(event->call_index, > host.used_idx, > - host.called_used_idx)) > - return; > + host.called_used_idx); > > host.called_used_idx = host.used_idx; > - call(); > + > + if (need) > + call(); > }
Acked-by: Jason Wang <jasowang@redhat.com>
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